Site Navigation

Site Mobile Navigation

The Origins of Jihadist-Inspired Attackers in the U.S.

All of the Sept. 11 attackers entered the United States using tourist, business or student visas. Since then, among attackers claiming or appearing to be motivated by extremist Islam, only one would have needed a visa to enter the United States at the time of the attack.Related Article

Sept. 11 attackers: tourist, business and student visas

After 9/11

Half of the attacks since 2001 were committed by men born in the United States.

U.S.-born citizen

Naturalized citizen

Green card

No visa needed

Tourist visa

The paths to violence for the United States-born attackers varied. Some were recent converts to Islam. At least three who were born in the U.S. had previous criminal histories, and one had a history of mental illness.

Security experts argue that the risks of routine travel — including the U.S. visa waiver program, which allows citizens of Britain, France, Belgium and 35 other countries to enter the United States without a visa for stays of up to 90 days — are greater than the threat of foreign terrorists coming through the refugee program.

“Further restricting the acceptance of refugees does not address the most likely vulnerability to attacks from abroad, which is the large number of people from visa-waiver countries involved in the conflict in Syria,” said David Sterman, a researcher for the International Security Program at the New America think tank who has been cataloging terrorist attacks carried out since Sept. 11.

Attacks With the Most Victims

U.S.-born

Green card

Syed Rizwan Farook and Tashfeen Malik, the couple suspected of killing 14 people and wounding 21 others at a social services center in San Bernardino, Calif., met online and had a 6-month-old baby. On the day of the assault, Ms. Malik posted on Facebook that the couple was dedicating the massacre to the Islamic State.

Mr. Farook was born in Illinois and raised in Southern California; his parents were born in Pakistan. Ms. Malik was born in Pakistan, grew up in Saudi Arabia and went to college in Pakistan. She moved to the United States in 2014 with a Pakistani passport and a K-1 visa, which designated her Mr. Farook’s fiancée. She was granted a conditional green card in July. After the attack, President Obama said that he had ordered a revision of the program under which Ms. Malik entered the country.

U.S.-born

Nidal Malik Hasan, who killed 13 people in a mass shooting at Fort Hood, Tex., in 2009, was born and raised in Virginia. Mr. Hasan had exchanged messages with Anwar al-Awlaki, an American radical cleric who was later killed by a drone strike in Yemen. Despite those exchanges, investigators have not linked Mr. Hasan’s attack to terrorism.

Naturalized citizen

Green card

Dzhokhar and Tamerlan Tsarnaev, the brothers responsible for the Boston Marathon bombings in 2013, settled in the United States after their parents were granted political asylum, which involves a less extensive vetting process than the program for Syrian and Iraqi refugees.

At the time of the Boston bombings, which killed three people and injured more than 260, Dzhokhar Tsarnaev was a naturalized American citizen, and Tamerlan had a green card.

Attacks by Foreign Residents

No visa needed

Tourist visa

Since 2001, “hardly any foreign-born have committed (or tried to commit) terrorism in (or on the way to) the U.S.,” John Mueller, a political scientist at Ohio State and the Cato Institute who tracks terrorism in the United States, wrote in an email.

Umar Farouk Abdulmutallab, a Nigerian man who tried to detonate explosives in his underwear during a flight from Amsterdam to Detroit in 2009, had a tourist visa. Richard C. Reid, who tried to detonate explosives in his shoes on a flight from Paris to Miami in 2001, is a British citizen, and would not have needed a visa to enter the United States.

In a speech after the attack in San Bernardino, Mr. Obama said he was working with Congress to strengthen screening of those who come to the United States without a visa, “so that we can take a hard look at whether they’ve traveled to war zones.”

Most Prominent Attacks Linked to Extremist Islam

2014

2014

Ali Muhammad Brown

U.S.-born citizen

Charged with murdering three men in Washington State and one in New Jersey.

Charged with murdering three men in Washington State and one in New Jersey.

2014

2014

Alton Nolen

U.S.-born citizen

Charged with first-degree murder in the beheading of a co-worker in Oklahoma.

Charged with first-degree murder in the beheading of a co-worker in Oklahoma.

2013

2013

Dzhokhar Tsarnaev

Naturalized citizen

Tamerlan Tsarnaev

Green card

The two brothers were responsible for the Boston Marathon bombings in 2013. Three people were killed and more than 260 were injured; an M.I.T. police officer was killed during the subsequent manhunt.

The two brothers were responsible for the Boston Marathon bombings in 2013. Three people were killed and more than 260 were injured; an M.I.T. police officer was killed during the subsequent manhunt.

2009

2009

Abdulhakim Mujahid Muhammad

U.S.-born citizen

Killed one soldier and wounded another at a military recruiting center in Little Rock, Ark.

Killed one soldier and wounded another at a military recruiting center in Little Rock, Ark.

2009

2009

Nidal Malik Hasan

U.S.-born citizen

Killed 13 people and wounded dozens of others in a shooting at Fort Hood in Texas.

Killed 13 people and wounded dozens of others in a shooting at Fort Hood in Texas.

2006

2006

Naveed Haq

U.S.-born citizen

Shot and killed one person and wounded five others at the Jewish Federation of Greater Seattle.

Shot and killed one person and wounded five others at the Jewish Federation of Greater Seattle.

2002

2002

Hesham Mohamed Hadayet

Green card

Fatally shot two people at the El Al ticket counter at Los Angeles International Airport.

Fatally shot two people at the El Al ticket counter at Los Angeles International Airport.

2015

2015

Elton Simpson

U.S.-born citizen

Nadir Hamid Soofi

U.S.-born citizen

Abdul Malik Abdul Kareem

U.S.-born citizen

Mr. Simpson and Mr. Soofi opened fire outside a gathering in Garland, Tex., that showcased artwork and cartoons depicting the Prophet Muhammad. Both men were killed by the police. Mr. Kareem was later charged with helping plan the attack.

Mr. Simpson and Mr. Soofi opened fire outside a gathering in Garland, Tex., that showcased artwork and cartoons depicting the Prophet Muhammad. Both men were killed by the police. Mr. Kareem was later charged with helping plan the attack.

2014

2014

Zale H. Thompson

U.S.-born citizen

Attacked police officers with a hatchet in New York.

Attacked police officers with a hatchet in New York.

2010

2010

Faisal Shahzad

Naturalized citizen

Planted a car bomb in Times Square.

Planted a car bomb in Times Square.

2010

2010

Yonathan Melaku

Naturalized citizen

Fired shots at five military buildings in the Washington area, including the Pentagon.

Fired shots at five military buildings in the Washington area, including the Pentagon.

2009

2009

Umar Farouk Abdulmutallab, Nigerian

Tourist visa

Tried to detonate explosives sewn into his underwear on a Detroit-bound airliner on Christmas Day.

Tried to detonate explosives sewn into his underwear on a Detroit-bound airliner on Christmas Day.

2006

2006

Mohammed Reza Taheri-azar

Naturalized citizen

Drove a sport utility vehicle through a crowded common area at the University of North Carolina at Chapel Hill.

Drove a sport utility vehicle through a crowded common area at the University of North Carolina at Chapel Hill.

2001

2001

Richard C. Reid, British

No visa needed

Tried to detonate explosives in his shoes during a flight from Paris to Miami.

Tried to detonate explosives in his shoes during a flight from Paris to Miami.

2015

2015

Mohammod Youssuf Abdulazeez

Naturalized citizen

Killed four Marines and one sailor at a military recruiting office in Chattanooga, Tenn.

Killed four Marines and one sailor at a military recruiting office in Chattanooga, Tenn.

2015

2015

Syed Rizwan Farook

U.S.-born citizen

Tashfeen Malik

Green card

Killed 14 people and wounded 21 others at a social services center in San Bernardino, Calif.

Killed 14 people and wounded 21 others at a social services center in San Bernardino, Calif.

Correction: An earlier version of this chart misstated the number of people killed during an attack at a military recruiting center in Chattanooga. It was five, not four.